Medical devices which are used to fragment and remove stones and other materials from, for example, the urinary tract, the bladder and the kidneys (hereinafter referred to as “stones”), are known in the art. An example of such a device is shown in U.S. Pat. No. 6,517,531. In this patent, a dual lumen elongated member is used, respectively, for the purposes of providing a first lumen for an optical fiber and a second lumen to aspirate fragmented stones or other materials.
One of the problems associated with the foregoing patent as well as other prior art is that a balance must be struck between the overall size or diameter of the device to be introduced into the urinary tract of a human being and to fit the working channel of an urethascope. The size should preferably be chosen not only so that it will fit within the space constraints above but also be of a size to be able to incorporate an aspiration lumen as well as a lumen to contain an optical fiber which is used to break apart, in this example, stones or other materials in urinary tract. As can be seen, FIG. 1 represents the prior art and it can be seen that the optical fiber lumen is contained within the aspiration lumen. This arrangement, of course, decreases the size of the aspiration lumen and limits the size of the degree of the stones or other fragmented materials which can be suctioned through the aspiration lumen to outside the body. Both FIGS. 1A and 1B show two variations of prior art systems which include the optical fiber lumen within the aspiration lumen. Thus, there is a need for a two lumen device which maintains the maximum size of the aspiration lumen so that larger pieces of fragmented stones or other materials may be aspirated while still containing sufficient space for the optical fiber lumen.
Another problem associated with dual lumen devices of the type of the present invention is that, as can be seen in prior art FIGS. 1A and 1B, the fiber lumen and the aspiration lumen terminate at the same plane. This results in the inability of the physician or other operator to visualize the optical fiber tip unless it is pushed out of the optical lumen. In a known procedure, in addition to the use of the device such as is described in the above patent and in the present invention an additional device named a urethascope is positioned in the body lumen and provides, among other things, a visualization lumen to the physician to visualize the materials sought to be removed and to guide the optical fiber. It is also known that during the process and procedure of fragmenting stones and other materials that the tip of the optical fiber may itself fragment due to the intense energy delivered through and at the tip of the optical fiber. Because the optical fiber lumen and the plane of the aspiration lumen terminate at the same plane, it is often difficult for the physician to inspect the tip of the optical fiber. Thus, what is needed is a dual lumen device which allows for easy visualization of the optical fiber tip.
Another issue associated with such devices described in the above patent and the present invention is the control of the optical fiber into the body cavity and its advancement within the body cavity to stones or other materials which are sought to be fragmented. Thus, what is needed is a simple and accurate means to move and control the position of the optical fiber and its tip in the urinary tract to better be able to aim the optical fiber tip at the stones to be fragmented.
Yet another issue associated with such devices is the ability to provide a handpiece that is easily gripped and manipulated by the operator of the device in use and which provides all controls for various functions, such as advancement of the optical fiber at gross movement levels and fine movement levels and control over the function of aspiration and irrigation within easy reach of the operator during a procedure.